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Finding the Fourth Proportional to 680.12, 938.54 and 385.45

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Solution

The fourth proportional to 680.12, 938.54 and 385.45 is: 531.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.12 : 938.54 = 385.45 : x
  2. Step 2: Convert to fraction form
    680.12/938.54 = 385.45/x
  3. Step 3: Cross multiply
    680.12x = 938.54 × 385.45
  4. Step 4: Simplify right side
    680.12x = 361,756.69
  5. Step 5: Solve for x
    x = 361,756.69/680.12
  6. Step 6: Final answer
    x = 531.90

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.